Hydroponic gardening, or the growing of plants in a fluid nutrient mix rather than in soil, has increased in popularity dramatically in recent years. The reasons are many and are generally a result of lack of space for conventional subterranean gardens and a lack of time for tending such conventional gardens.
In hydroponic gardening a nutrient solution provides all of the elements essential to plant growth and development. In soil-grown plants, the plants must develop a large root system in order to span the distances necessary to obtain a balanced supply of nutrients from the soil. Development of such a large root system necessarily reduces the overall growth of the plant and its fruit production. Conversely, hydroponic gardening systems provide a constant, balanced supply of the essential nutrients to the plants and thereby eliminates the need for development of large root systems. Because the need for large root systems is eliminated in hydroponic gardening, it is possible to grow much larger plants and a larger number of plants in a substantially smaller area. Plant selection and spacing is limited only by available light sources.
In most of the known hydroponic systems on the market today, an electric pump is required to circulate and thereby aerate the nutrient fluid. Plant roots use the oxygen which is dissolved in water and when the oxygen is not replaced, the root system is damaged to the point of killing the plant. For example, in overwatered soil-grown plants, water fills the airspaces between the soil particles and as the plant uses the available oxygen dissolved in that water, and is without access to more oxygen, the root system dies.
Another well-known approach to hydroponic gardening is a wick system wherein the growing medium or seed cubes are kept moist by strips of wicking material that hang into the nutrient tank below the growing medium and feeds fluids by wicking action to the plants. Such wick systems are somewhat satisfactory for growing small plants but are grossly insufficient for delivery of nutrient fluid to larger plants which require substantial and continuous fluid supply for good production of fruits and vegetables.
The present invention overcomes the problems with known hydroponic systems, eliminating the need for a pump to aerate the nutrient and also providing a sufficient nutrient supply to plants of any size. Even large plants such as tomatoes are successfully grown in the present system. In the improved hydroponic systems, a unique multilevel aeration chamber is built into the plant support tray or portion of the gardening apparatus. This multilevel aeration chamber is separate from and positioned above the nutrient fluid tank so that the plant root systems which develop in the aeration chamber are constantly exposed to freely circulating air that is kept at 100 percent relative humidity. This multilevel arrangement gives the root system a constant supply of oxygen from the circulating air, without the problem of drowning the root system in a nutrient fluid supply that is not mechanically aerated. The small portion of the root system that grows in the nutrient fluid reservoir is kept alive by diffusion of oxygen from the root mass which grows in the multilevel aeration chamber.
The root system growing in the multilevel aeration chamber is supplied continuously with nutrient fluid by use of a capillary mat that covers the plurality of support surfaces or floors in the aeration chamber, and the ends of which mat extend down into the nutrient fluid tank. By capillary action, nutrient fluid moves upwardly along the fibers of the mat and thereby is supplied to the root system in the aeration chamber and to the growing medium. Access covers are provided to allow viewing the root system without disturbing root formation, and to allow for the replenishment of nutrient fluid.
The apparatus of growing unit is formed from a rigid and durable polymeric material and is provided in various sizes and with various arrangements of the growing medium and associated access covers. It was a primary objective of the present invention to provide an improved hydroponic gardening apparatus and system wherein the nutrient fluid and plant root systems could be aerated and thereby supplied with oxygen, without the use of expensive mechanical pumps and timers. It was also an objective of the invention to provide a multilevel aeration chamber in a hydroponic gardening system, through which chamber air freely circulates and supplies the plant root systems with a constant supply of oxygen while maintaining 100 percent relative humidity in the chamber. It was also an objective to provide a compact hydroponic system for growing plants of any size, and one particularly for development of larger plants which have previously been difficult to grow in hydroponic systems. Other and further objectives and advantages of the present invention will become apparent when the following detailed description is studied in conjunction with the accompanying drawings.